Lisa - as far as I am aware, tandem nursing amongst the indigenous
population in Zimbabwe is never practised.  The older baby/child is weaned
on the turn as soon as the mother discovers a new pregnancy because it is
believed that the milk turns "poisonous".  Sometimes the nursling is even
given an emetic so that s/he will vomit up the last milk ingested.  I have
had two clients who delivered their second babies in a private clinic and
nursed their older toddlers during visiting hours.  The first time the
nursing staff were shocked to the core, the second time they were a little
more accepting - I guess we can slowly educate people, one mother at a time ..

Pamela Morrison IBCLC, Zimbabwe